During the last few years, information services used and supplied via various information networks, particularly the Internet, have increased enormously. The end users of these services are provided with information on countless different topics and sources. Most information services, for example those provided via the Internet, are ‘free’ to the end user, i.e. the end user does not pay anything for the use of the information service, only for the telecommunication links used and, possibly, a basic fee to an Internet service provider. However, the creation and maintenance of information services provided in information networks typically cause costs to the providers of the information services in an information network, and these costs may be covered for instance by selling advertising space in association with an information service.
The enormous amount of information available on the Internet, for example, causes difficulties in finding the right information. Each end user typically has specific interests, preferences and information needs, and to find even the most important of them on the Internet is often unreasonably difficult and time-consuming. Similarly, as regards the providers of information services, it would be wise to direct each information service to end users who are interested in that specific information. This end also serves advertisers, since the ability to direct the content of an information service more exactly to an interested end user allows an advertiser to specify target groups more exactly. Consequently, the ability to easily and rapidly find and present information in the information network to an interested end user serves the ends of both the service provider and the advertiser.
Methods have been developed for this purpose, which allow the Internet home page or another similar browser page of the end user to be personalized, i.e. the information and hyperlinks comprised by the page to be modified to conform to the end user's preferences and information needs. Such methods are disclosed in e.g. WO 00/08573, EP 1065614, EP 855659, WO 99/63416, U.S. Pat. Nos. 5,790,935, 5,754,938 and DE 4440419.
A problem in these known methods is that they are based solely on quantitative information about the end user and the use history directed by the end user to a given information service. From the point of view of a provider of an information service, such quantitative information only indicates the type of information an end user is interested in, but not what the end user's reaction was and if the end user was satisfied with the information content presented and the way it was presented. Thus, a provider of an information service and an advertiser do not obtain sufficiently accurately modelled feedback about the way the content of an information service should be modified in order for the content of the information service to be as optimal as possible to all parties.